In the past there have been numerous types of devices which have been utilized for a person having an injured or broken arm such as the well known plaster cast. This invention is of an upper arm brace which is adapted to be secured about the arm of wearer and wherein a posterior and an anterior segment are provided for clamping or clam shell type interengagement with one another about the arm of the wearer to apply pressure to the flesh to support the upper arm. The device includes a fastening means and adjustment means to adjust and maintain the amount of pressure which is applied by the two segments when in nested relations which one another and about the arm of a wearer. The segments have contoured surfaces to nest comfortably along the bicep as well as a cut away segment area at the end of the arm brace adjacent to the armpit to allow for full range of movement of the upper arm.